582 The Philippine Journal of Science 1921 
with the descriptions of sixteen new species of Mecistocerus 55 
the same author adds two supplementary notes, and finally 
proposes a new genus, 66 Isotocerus, for I. petax Faust, a new 
Papuan species, the rostral canal of which extends toward the 
middle of the intermediate coxse. 
Nevertheless, M. A. Lea, the highly esteemed connoisseur of 
the Australian fauna, in his key of Australian Cryptorhynchidse, 
has cited the two genera Mecistocerus and Berosiris as different, 
differentiating them by a lamella on the metasternum which 
limits the rostral canal on each side in Mecistocerus , but which 
is wanting (according to Lea) in Berosiris. As a matter of 
fact, the type species of the latter, marci Boh., shows this 
lamella quite as well developed as in impressus Fauvel and there- 
fore the genus Berosiris of Lea is different from Berosiris of 
Pascoe. I propose for the first the name Riboseris, the type 
of which is mixtus Lea. 
On this occasion may be mentioned a series of Mecistocerus 
species described by Lea, which he says he received from J. 
Faust. As all these are now wanting in Faust’s collection I 
suppose they were single specimens. 
Also, I must correct an error of Faust in creating the genus 
Isotocerus, of which he says that the rostral canal, extending 
distinctly beyond the intermediate coxae in Mecistocerus, reaches 
only to the middle in Isotocerus. In examining this character 
I found that in twenty-eight Indo-Malayan species the rostral 
canal reaches the hind margin of intermediate coxae and in only 
eight species ( marci Boh., subundatus Schonh., nigrostriatus 
Chevr., corticeus Faust, offensus Faust, subcylindricus Faust, 
caliginosus Faust, and devotus Pasc.) it extends distinctly to 
or beyond the hind margin. Also, the other characters of Iso- 
tocerus , indicated by Faust, agree only partly. I see no differ- 
ence between Mecistocerus and Isotocerus, either in the antennal 
furrow or in the base of the hind femora which is said to 
be not naked above in Isotocerus, for I. petax Faust shows a 
greater extension of naked area than does Mecistocerus impres- 
sus Fauv. 
The similar Papuan species of Isotocerus have for the most 
part an impressed profile at the base of the rostrum, but 
Mecistocerus incertus Pasc. represents a transition to this, so 
that this character is also untenable. 
66 Ann. Mus. Genova 34 (1895) 265, 279. 
65 Stettin. Ent. Zeit. 59 (1898) 145. 
